Spatiotemporal tendency of agricultural water use efficiency in the northernmost Yellow River: Indicator comparison and interactive driving factors

Abstract

Water use efficiency (WUE) is calculated as the ratio between the gross primary productivity (GPP) and the water consumed by evapotranspiration (ET) or vegetation transpiration (Et). The evapotranspiration of Hetao irrigation District is very large, and the WUE of this area is affected by many factors. At present, the correlation analysis of multi factor interaction has not been carried out. A comparison of the spatiotemporal patterns as well as the impact of meteorological factors on the WUE of ecosystems (WUEe) and the WUE of canopies (WUEc) in the Hetao Irrigation District can provide a fundamental basis for water management at the basin level, especially in dryland irrigation areas. Trend analysis indicated that the trends of WUEe and WUEc had opposite directions, namely, the increase in WUEe concealed the decrease in WUEc based on the application of remotely sensed GPP and ET products in the Hetao Irrigation District. In addition, WUEe and WUEc had different responses to meteorological factors. The interactive influence of multiple climate factor interactions on WUE was greater than the influence of single factors. The identification of the response of WUE to meteorological factors can provide a scientific basis for farmland water replenishment in arid areas.